Prosthetic heart valves are normally tested for durability in accordance with the ISO5840 standard which calls for 200 million cycles of testing. In order to achieve these huge cycle numbers in a reasonable time the cycle rate may be set to 1200 cycles per minute or more. The standard requires that a certain proportion of each cycle (e.g. 5%) be at or above a certain reverse pressure.
It is difficult to perform accelerated tests that comply with the requirements of ISO 5840 and other standards because many common valves are made from animal tissue and are quite flexible. This fact combined with the high cycle rate and fluid dynamic effects can make it hard to test heart valves in a manner that complies with applicable standards.
Excess reverse pressure can cause heart valves to fail prematurely. Some valve testing apparatus causes pressure spikes or applies other excess pressures which can result in false testing failures.
There is a need for methods and apparatus for testing heart valves that are reliable and operate according to desired testing protocols. There is also a need for methods and apparatus capable of executing new testing protocols that may provide enhanced information about the long term reliability of heart valves being tested.